A lattice Boltzmann based single-phase method for modeling surface tension and wetting

A 2D single-phase free surface tracking model using the lattice Boltzmann method (LBM) is developed in this study. In contrast to the conventional multi-phase models, it is not necessary to simulate the motion of the gas phase using such LBM single-phase algorithm, and thus improves the computational efficiency without sacrificing the underlying physics. Based on Gunstensen's immiscible lattice Boltzmann algorithm, a perturbation is added to the distribution functions of the interface cells for incorporating the surface tension and wetting into the LBM single-phase model. Implementations of the model are demonstrated for simulating the droplet deformation under the surface tension effect, the droplet spreading on solid surface and the capillary rise with various wetting properties. Simulation results show that the proposed model can generate a surface tension that is isotropic, and the model allows for continuous control of the contact angle by varying the mass gradient at the wall boundary cells.